Goodwill and Intangible Assets (Tables)

9 Months Ended

Sep. 30, 2018

Goodwill And Intangible Assets Disclosure [Abstract]

Goodwill by Operating Segment

Goodwill — Goodwill by operating segment as of September 30, 2018 and changes for the nine months then ended are as follows (in thousands):

	Contract		Pressure		Directional		Oilfield
	Drilling		Pumping		Drilling		Rentals		Total
Balance at beginning of period	$	395,060		121,444	$	88,685		6,284	$	611,473
Changes to goodwill		—		—		1,000		—		1,000
Balance at end of period	$	395,060	$	121,444	$	89,685	$	6,284	$	612,473

Gross Carrying Amount and Accumulated Amortization of Intangible Assets

Intangible Assets — The following table presents the gross carrying amount and accumulated amortization of the intangible assets as of September 30, 2018 and December 31, 2017 (in thousands):

	September 30, 2018							December 31, 2017
	Gross					Net		Gross					Net
	Carrying		Accumulated			Carrying		Carrying		Accumulated			Carrying
	Amount		Amortization			Amount		Amount		Amortization			Amount
Customer relationships	$	26,200	$	(8,493	)		17,707	$	26,200	$	(1,943	)	$	24,257
Developed technology		55,772		(5,139	)		50,633		48,000		(1,137	)		46,863
Favorable drilling contracts		22,500		(22,336	)		164		22,500		(18,482	)		4,018
Internal use software		482		(94	)		388		482		(21	)		461
	$	104,954	$	(36,062	)	$	68,892	$	97,182	$	(21,583	)	$	75,599